Structure, composition and electrical properties of YSZ films deposited by ultrasonic spray pyrolysis

Yttria-stabilized zirconia (YSZ) films with different yttria concentrations were prepared by ultrasonic spray pyrolysis on Si substrates at 525 C, using solutions of zirconium and yttrium acetylacetonates in methanol. The chemical composition, structure and electrical properties of the films were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS). XPS measurements show that the Y content in the films increases as the Y precursor in the solution increases. Carbon incorporation was also found in the films, although the concentration of this impurity was reduced as the incorporation of Y increased. XRD spectra show that the Zr1–xYxO2–x/2 polycrystalline films have the cubic phase of ZrO2 and fully stabilized 8YSZ (8 at.% Y2O3 + 92 at.% ZrO2), and that their lattice constant increases slightly as the Y content increases. The conductivity of all the as-deposited films as a function of temperature, showed an Arrhenius behavior, and with the exception of the film with the maximum Y content, the activation energies were in the range of 0.98–1.11 eV. The ionic conductivity of one of these films was similar to that measured for a pellet made of the 8YSZ standard powder.